Furnaces for heating and assembling metallic composite units



J. a ULAM 5 FURNACES FOR HEATING AND ASSEMBLING METALLIC COMPOSITE UNITSFiled July 25, 1962 XNVENTOR John B. Ulum United States Patent 3,19%,524FURNAQES EGR HEATING AND AdSEh/IIELING METALLIC CIIMIPOSITE UNITS IolmII. Iliam, *Canonsburg, Pan, assignor to tCornposite Metal Products,Inc. File-:1 Italy 25, I962, der. No. 212,298 9 @Ciaims. (El. 22$4) Thisinvention relates to furnaces for heating and assembling metal compositebodies and particularly to a furnace for heating multiple strands ofmetal and assembling said multiple strands into a composite within theconfines of the furnace.

In the manufacture of metallic composite bodies where, for example, aninner layer of aluminum is placed between two outer layers of stainlesssteel to form a single composite element, great difficulty has beenexperienced in properly heating the several strands and bringing themtogether without oxidizing the facing surfaces, through which the bondis established. I have pointed out in my Patent 2,758,368 that it isimperative that the surfaces which are to be brought together be cleanedby a mechanical cleaning process and that those cleaned surfaces must bemaintained clean and free of oxidation product if a satisfactory bond isto be achieved. This has posed real problems in heating and handling thestrip during the formation of the composite and its introduction intothe rolling mill. I have invented a furnace which is capable ofdelivering a multiplicity of strands of metal properly cleaned andheated out of the furnace in the form of a single composite unit whichmay go directly to the reduc tion mills to form a composite and toreduce the composite to its final shape.

Preferably, I provide a furnace having an elongated housing, a heatingportion and an exit portion, a central conveyor extending midway betweenthe top and the bottom and adapted to carry a sheet or plate of coremetal, spaced above and below this center hearth are longitudinallyextending passageways each adapted to receive a strip for forming theouter surface layer of the composite, heating means are provided in theheating portion of the furnace heating the several strands in thefurnace body, a pair of bending rolls in the exit chamber on each sideof the line of travel of the center strip, said bending rolls bendingthe upper and lower strips toward the center and again parallel to, andin contact with the central strand, a pair of pinch rolls in the exitportion adjacent the bending rolls, one on each side of the center lineof the central strip, receiving all of the strands therebetween andurging the strands into intimate contact and an exit opening in thefurnace adjacent the pinch rolls sealingly engaging the strip leavingthe pinch rolls through which the strip passes from the interior of thefurnace.

In the foregoing general description, I have set out certain objects,purposes and advantages of my invention. Other objects, purposes andadvantages will be apparent from a consideration of the followingdescription and the accompanying drawings in which-- FIGURE 1 is asideelevation of a furnace according to this invention;

FIGURE 2 is a section on the line II-II of FIGURE 1;

FIGURE 3 is an isometric view of a segment of the furnace broken away toshow the heating means; and

FIGURE 4 is an enlarged segmental isometric view of a baffle arrangementfor use in the furnace of this invention.

Referring to the drawings, I have illustrated a furnace Iii having aheating portion Ilia and an exit chamber or portion Itib and having acentral roll conveyor II, extending lengthwise of the furnace. Spacedstrip conveyor entrance rolls I2 and 13 are provided on opposite sidesof the roll conveyors 11. The conveyors II are adapted to carry acentral core of metal 14-. The conveyor rolls I2 and i3 carry a strip ofmetal 15 and I6 respectively against skid rails 17 on the bottom of thefurnace and I? on the top of the furnace. The strip 15 and the strip 16are heated by gas passing across radiant tubes 19 and 20 respectivelywhich extend transversely of the furnace to an exhaust stack 21. Thegases pass from the radiant tubes through jet plates 22. The central orcore strand passes between jet plates 24 on opposite sides of the rollconveyor whereby the strip is heated. The central strand 14 reaches theexit chamber Iiib through an opening 23 along with heated gases from theheating portion into the furnace exit chamber 1%, where it passesbetween bending rolls 25 and pinch rolls SI. The two strands I5 and 15pass from the furnace along with heated gases from the furnace into exitchamber lttib. The heated gases maintain the heating chamber and thebending and pinch rolls at a temperature sufficient to promote bondingof the metal in the pinch rolls. Bending rolls 29 and 3t bend the twostrands I5 and I6 upwardly and downwardly respectively into the bendingrolls 25 which bend the strands I5 and 16 into parallelism with thecentral strip 14, and into contact with said central strip. The threeelements I4, 15 and 16 are then passed into pinch rolls 31 within theexit chamber fill; which urges the three components I4, I5 and 16 intointimate contact and feeds them in contact with one another through theexit opening 32 into pinch rolls 33 feeding the rolling mill strand.

The atmosphere in the furnace chamber and in the exit chamber is onethat is compatible with maintenance of oxide free conditions on thesurfaces of the metal components 14, I5 and 16, for example, argon,hydrogen, nitrogen or any other gas which will produce the desiredresult. This protective gas may be introduced in conventional manner.

The heating structure is most clearly shown in FIGURE 3. The protectivegas is drawn through slots 4t into the heating intake cell 41, acrossthe radiant tubes 19 where it is heated. A fan 12 draws the gas from theheating intake cell ill into fan housing 42a and discharges it intoheating discharge cell 4-3 and through perforated jet plates 22 and 24onto the surfaces of the several strips to be heated. The fan 42 ispreferably driven from a motor 44 mounted externally of the furnace.Movable baflies 45 above and below jet plates 24 which control the flowof heat the strip 14- permit the temperature of the strip 14- to bevaried with respect to strips 15 and 16 so that the three strips may beheated to different temperatures in the furnace units.

In the foregoing specification, I have set out certain preferredembodiments of my furnace. It will be understood, however, that thisinvention may be otherwise embodied within the scope of the followingclaims.

I claim:

I. A furnace for heating and combining a plurality of strips to beformed into a single member comprising an elongated housing, having aheating portion and an exit portion, a conveyor means extendinglengthwise of the housing intermediate the top and bottom thereof andadapted to convey a strip therethrough, a second conveyor means spacedfrom and on one side of said central conveyor adapted to carry a secondstrip therethrough, heating means acting on the adjacent sides of saidstrips in the heating portion, bending rolls acting on at least one ofthe two strips adapted to guide them into contact With one another inthe exit portion and means applying pres sure on said pieces in the exitportion to bond them and feed them out of said furnace as a singlestrand.

2. A furnace for heating and combining a plurality of strips to beformed into a single member comprising an elongated housing, having aheat-ing portion and an exit portion, a conveyor means extendinglengthwise of the housing intermediate the top and bottom thereof andadapted to convey a strip therethrough, a second conveyor means spacedfrom and on one side of said central conveyor adapted to carry a secondstrip therethrough, heating means acting on the adjacent sides of saidstrips in the heating portion, bending rolls acting on at least one ofthe two strips adapted to guide them into contact with one another inthe exit portion, means for maintaining a common protective atmospherewithin the heating portion and the exit portion and means applyingpressure on said pieces in the exit portion to bond them and feed themout of said furnace as a single strand.

3. A furnace for heating and combining a plurality of strips to beformed into a single member comprising an elongated housing, having aheating portion and an exit portion, a conveyor means extendinglengthwise of the housing intermediate the top and bottom thereof andadapted to convey a first strip therethrough, a second conveyor meansspaced from and on one side of said central conveyor adapted to carry asecond strip therethrough, a third conveyor means spaced from and on theopposite side of said central conveyor from the second conveyor adaptedto carry a third strip therethrough, heating means acting on theadjacent sides of said strips in the heating portion, bending rolls inthe exit portion between the first strip and each of the second andthird strips adapted to guide said second and third strips into contactwith the first strip on opposite sides thereof and means applyingpressure on said pieces in the exit portion to bond them and feed themout of said furnace as a single strand.

4. A furnace for heating and combining a plurality of strips to beformed into a single member comprising an eiongated housing, having aheating portion and an exit portion, a conveyor means extendinglengthwise of the housing intermediate the top and bottom thereof andadapted to convey a strip therethrough, a second conveyor means spacedfrom and on one side of said central conveyor adapted to carry a secondstrip therethrough, heating means acting on the adjacent sides of saidstrips in the heating portion, said heating means including a pluralityof recirculating heating cells adapted to direct a heated gas over aheat source onto the surfaces to be heated and return the gas to theheat source for reheating, bending rolls acting on at least one of thetwo strips adapted to guide them into contact with one another in theexit portion and means applying pressure on said pieces in the exitportion to bond them and feed them out of said furnace as a singlestrand.

5. A furnace as claimed in claim '4 wherein the gas is a gas selectedfrom the group consisting of hydrogen, nitrogen and the inert gases.

6. A furnace for heating and combining a plurality of strips to beformed into a single member comprising an elongated housing, having aheating portion and an exit portion, roll conveyor means extendinglengthwise of the housing intermediate the top and bottom thereof andadapted to convey a first strip therethrough, a second conveyor meansspaced from and on one side of said central conveyor adapted to carry asecond strip therethrough, heating means acting on the adjacent sides ofsaid strips in the heating portion, a bending roll on the path of travelof the second strip adapted to bend the second strip toward the firststrip, a second bending roll adjacent the path of the first stripadapted to bend the second strip into contact with said first strip inthe exit portion and pinch roll means applying pressure on said piecesin the exit portion to bond them and feed them out of said furnace as asingle strand.

7. A furnace for heating and combining a plurality of strips to beformed into a single member comprising an elongated housing, having aheating portion and an exit portion, a conveyor means extendinglengthwise of the housing intermediate the top and bottom thereof andadapted to convey a strip therethrough, a second coneyor means spacedfrom and on one side of said central conveyor adapted to carry a secondstrip therethrough, heating means acting on the adjacent sides of saidstrips in the heating portion to heat said strips to different selectedtemperatures, bending rolls acting on at least one of the two stripsadapted to guide them into contact with one another in the exit portionand means applying pressure on said pieces in the exit portion to bondthem and feed them out of said furnace as a single strand.

8. A furnace as claimed in claim 7 wherein the heating means includesmovable battles restricting the flow of heat to selected surfaces.

9. A furnace as claimed in claim '7 wherein the heating means acts onthe plurality of strips in both the heating and exit portions.

References Cited by the Examiner UNITED STATES PATENTS Re. 11,927 8/01Allis 2 2,133,051 10/38 Bollinger 802 2,205,182 6/40 Whitten 80-22,349,569 5/44 \Vilson 2l9-l0.61 2,499,191 2/50 Jones 2633 2,691,20810/54 Brennan 78-82 2,797,074 6/57 Flynn 2633 2,921,778 1/60 Ruff 263-3WILLIAM J. STEPHENSON, Primary Examiner.

CHARLES W. LANHAM, Examiner.

1. A FRAME FOR HEATING AND COMBINING A PLURALITY OF STRIPS TO BE FORMEDINTO A SINGLE MEMBER COMPRISING AN ELONGATED HOUSING, HAVING A HEATINGPORTION AND AN EXIT PORTION, A CONVEYOR MEANS EXTENDING LENGTHWISE OFTHE HOUSING INTERMEDIATE THE TOP AND BOTTOM THEREOF AND ADAPTED TOCONVEY A STRIP THERETHROUGH, A SECOND CONVEYOR MEANS SPACED FROM AND ONONE SIDE OF SAID CENTRAL CONVEYOR ADAPTED TO CARRY A SECOND STRIPTHERETHROUGH, HEATING MEANS ACTING ON THE ADJACENT SIDES OF SAID STRIPSIN THE HEATING PORTION, BENDING ROLLS ACTING ON AT LEAST ONE THE TWOSTRIPS ADAPTED TO GUIDE THEM INTO CONTACT WITH ONE ANOTHER IN THE EXITPORTION AND MEANS APPLYING PRESSURE ON SAID PIECES IN THE EXIT PORTIONTO BOND THEM AND FEED THEM OUT OF SAID FURNACE AS A SINGLE STRAND.